The present invention relates to a disk concentrator utilizing filter disks which are arranged for rotation, essentially parallel with one another in a trough. The filter disks are at a mutual distance from one another and each filter disk has at least one screen surface or screen area. The screen surfaces are combined together in pairs to produce filter chambers. A suspension inlet is situated on one of the side end walls of the trough upstream of the filter chamber in relation to the flow therethrough. The concentrator serves to remove the filtrate from aqueous suspensions containing fibrous components such as a paper or wastepaper suspension.
One prior art disk concentrator of a similar type is disclosed in DE-A32 35 003. This prior art disk concentrator includes filter chambers made up of adjacent filter disks. The filter chambers contain the introduced suspension and are open at their radial edge. These filter chambers, together with rotating seals attached thereto, alternately make up, together with corresponding flange-like projections on the trough, chambers for the filtrate. In each case, the chambers for the filtrate must be provided with an outlet which is separated from the rest of the contents of the trough. In this previously disclosed arrangement, the filtrate outlet from the filtrate chambers is located on the floor of the trough and at the lowest part of the filtrate chambers. A considerable disadvantage of this prior art design is the presence of many sliding seals, because in each case, the filter chambers must be sealed against the adjacent filter chamber. Furthermore, the prior art design is disadvantageous in that the seals are arranged in an area of high peripheral speed.
Other disk concentrators of similar construction are known to serve primarily for the recovery of fibrous material from the effluent or recirculating water which is present as part of the paper manufacturing process. In these disk concentrators, a dense filter cake is produced on the screen material by means of negative pressure inside the filter disks. The negative pressure or vacuum is provided via vertical pipelines. In one of these prior art embodiments, according to DE-AS 26 26 458, it has been attempted to create a concentrator or to provide the effect of a concentrator by various specific methods. These methods include the use of a means to create turbulence in the flow, essentially in the vicinity of the filter disks in order to prevent the rapid formation of a dense filter cake on the screen material. In practice, however, this method has proved to be generally unsuccessful.